Spring officially begins today (March 20) with the vernal equinox, bringing longer days and warmer temperatures to the Northern Hemisphere. The vernal equinox signals the astronomical start of spring ...

An Iranian man jumps over a firework celebrating Chaharshanbe Souri, or Wednesday Feast, an ancient Festival of Fire on the eve of the last Wednesday of the Persian year, in Tehran, Iran, Tuesday.

The autumn equinox is now upon us! Today marks the moment that the sun crosses the celestial equator, ushering in the beginning of astronomical autumn in the northern hemisphere, which brings with it ...

Spring is here — officially, at least. The vernal equinox arrives on Thursday, marking the start of the spring season for the Northern Hemisphere and the fall in the Southern Hemisphere. On the ...

A new NASA study has uncovered an unexpected and unsettling shift: Earth has grown a full shade darker since 2001. This means ...

Peak sunshine has arrived in the Northern Hemisphere — the summer solstice. Friday is the longest day of the year north of the equator, where the solstice marks the start of astronomical summer. It’s ...